The Phinjury Report: ACL Tears

When you hear the letters “ACL” you often think of a player falling down with no contact and joining the injured reserve for the rest of the season. The anterior crucial ligament or ACL tear is one of the most career threatening injuries due to its long recovery time and high risk of re-injury. Today we will be reviewing the ACL tear because many dolphins’ players are at risk including, Kiko Alonso, Brandon Albert, Jay Ajayi, and new addition Chris Culliver.

What is the ACL?

I can still remember my professor and I working in the cadaver lab to expose the ACL ligament, surprisingly, it was extremely dissatisfying. The ACL is a very small ligament that runs from the back of the femur, forward to the top of the tibia, inside the knee. Ligaments require a lengthy period of time to heal due to poor blood supply. The ligament works to prevent anterior translation aka the shinbone moving forward, away from the thighbone, such as, when you bend your knee.

How injury occurs and is treated.

There are two mechanisms of injury for the ACL, contact and non-contact. Contact ACL tears often occur when a player is hit from behind at an angle just below the knee, resulting in the shinbone being driven forward and away from the rest of the leg. This movement creates a large shearing force through the ACL causing it to tear. The more common non-contact ACL tear occurs when a player is cutting towards the sidelines and the plant leg turns internally and the knee bends. The large amount of force produced by players at full sprint cannot be maintained by the ACL and results in a tear. Complications with this injury include the tearing of the medial meniscus, medial collateral ligament (MCL) and posterior collateral ligament (PCL). Injuries to these support structures translate to more complicated healing procedures and reduced support for the knee even after surgery.
Surgery is required for NFL players and there are many different approaches to reconstruct the ACL. Most players transplant a ligament from a different part of their body. The most common procedure involves a graft of the patella tendon. The video below provides a clear visual example of how the surgery is performed.

According to the American Physical Therapy Association1 (APTA) protocol for ACL reconstruction, there are six main steps involved after ACL surgery. Eliminating pain and swelling from the knee, restoring full knee range of motion specifically straightening the leg, restoring mobility of the patella (knee cap), restoring strength in the quadriceps muscle, and finally restoring weight bearing gait. The first 6-8 weeks after the surgery involve an immobility knee brace to prevent unwanted movement. After the immobility brace is removed, functional training begins. Beginning activities include straight-line running, squatting and other strengthening exercises. Sport specific activities can begin once the surgically repaired leg is 90% as strong as the unaffected leg. Strength is commonly measured using the single leg vertical jump test.

The most dangerous time for re-injury to occur is 3-9 months after the surgery when sports specific activity begins. The ligament is not always fully healed and if the athlete is rushed in their therapeutic progression, re-injury can occur quite easily. Because of this high rate of re-injury when players are coming back from ACL reconstruction a conservative approach towards therapy is always best.

Dolphins affected by ACL injuries.

Since there are multiple members of the dolphins who have been through ACL reconstruction in the past, I want to break them down here.

Kiko Alonso (2014)

Acquired in that controversial trade with the Philadelphia Eagles this off-season. After Alonso’s rookie season with the Bills he reportedly tore his left ACL during off-season training and missed the entirety of the 2014 season. Last year on the Philadelphia Eagles he had mild success but in week 2 suffered a reported partial tear of the surgically repaired left ACL. This injury reportedly required an additional knee scope to clean out parts of the ligament, which were torn off. While there have been no flair ups this off-season Kiko should be under the strict eye of the training staff.

Brandon Albert (2014),

Below is a video of the play in which Brandon Albert’s tore his ACL, it is the best example of a contact ACL tear I’ve seen (possibly include a video below?). After missing the 2015 preseason Albert’s started every game last year except for weeks 3 and 4 due to an unrelated hamstring strain. While Albert’s play has been up and down this preseason reports have been that he lost weight to take stress of his joints and has been playing injury free. Overall I believe Brandon Albert should be at low risk of ACL re-injury.

Jay Ajayi’s right knee has been a topic of conversation ever since we drafted him in 2015. After tearing his ACL his freshmen year at Boise State the RB was considered a 1st or 2nd round talent but due to reports of bone on bone contact in the repaired knee, his stock fell to us in the 5th round. Bone on bone contact can be a concern as it reduces the amount of shock absorption provided by the knee, which increases the possibility of early onset osteoarthritis and stress fractures. Reports out of camp state that Ajayi has a bone bruise but on the left knee after colliding with another player. Ajayi will need to be continually monitored by the training staff to ensure a healthy season.

Chris Culliver(2014)

Chris Culliver is a recent addition to the roster; he was signed on the team after being released by the Washington Redskin’s last year. Culliver reportedly tore his ACL during a practice last November and is still recovering. Culliver will continue his rehab on the PUP list for at least the first six weeks of the season. As stated above Culliver is now in the most critical period of rehab, where he will begin sport specific activities while the ACL may not be at full strength. Hopefully the training staff will be working very closely with Culliver to prevent mishaps and get him back on the field in a position already thin on our roster.

What the Research shows.

The main concern for all of these players with past ACL tears is the high risk of reinjury. Three different research studies show that players with past ACL tears are up to 6 times more likely than uninjured players to reinjure the same knee along with a 25% increase in tearing the ACL of the opposite knee2, 3,4. Another big factor sited in recent research on re-injury of the ACL5, is the age when the initial injury to the knee occurs. ACL tears occurring before the age of 25 (Ajayi and Alonso come to mind) are 62% more likely to tear either ACL than the average player.

“Past history of injury is the best predictor of future injury” is a quote I often remember being told while in school. Based on the scientific research and the past history of players in the NFL with ACL injuries, the odds of one of the four players listed having ACL issues this season is extremely high. While the medical team will be diligently working to prevent re-injury, this information supports the importance of having quality depth on our Miami Dolphins football roster.

4: Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture”. British Journal of Sports Medicine. 2016.